Wiedemeyer K, et al. - This study was carried out to assess the prevalence of this biomarker in ovarian clear cell carcinoma (OCCC) in a mixed-ethnicity Canadian population and to explore relationships of glypican-3 (GPC3) expression with clinicopathological parameters. Researchers applied a GPC3 antibody clone 1G12 to analyze tissue microarrays with napsin A or HNF1β positive and WT1-negative OCCC specimens. They reported membranous, cytoplasmic, and Golgi pattern GPC3 expression in 184 of 316 (58.2%) cases; 63 of 316 (20%) cases revealed high GPC3 expression (>50% of tumor cells were positive). The results indicated that women diagnosed with OCCC and high GPC3 expression were also more likely to receive adjuvant chemotherapy. It was showed that GPC3 immunohistochemistry is a robust predictive test for inclusion in clinical trials for GPC3-targeted therapies for OCCC considering the tumor-specific membranous expression of GPC3 in 58% of cases and high interobserver reproducibility.